A flexible display module, under-screen fingerprint display device and manufacturing method

Abstract

The present invention discloses a flexible display module, an under-screen fingerprint display device and a manufacturing method, wherein the flexible display module comprises a display panel, a heat dissipation film and a light-shielding tape, wherein the heat dissipation film comprises a first film layer, a second film layer and a protective film layer which are sequentially stacked and arranged on the display panel away from the light-emitting side, wherein the first film layer comprises a first opening therethrough, and the first opening corresponds to the sensing area of ​​the fingerprint recognition module to be installed in the flexible display module; the second film layer comprises a second opening therethrough, and the second opening is arranged corresponding to the first opening to expose the sensing area of ​​the fingerprint recognition module to be installed, and the aperture of the second opening is larger than the aperture of the first opening; the protective film layer covers the second film layer; the light-shielding tape is arranged on the side of the protective film layer close to the display panel and is located in the second opening, and the orthographic projection of the light-shielding tape on the display panel covers the orthographic projection of the first opening on the display panel. The present invention can effectively reduce the mold printing at the opening of the display panel.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a flexible display module, an under-screen fingerprint display device and a manufacturing method. Background Art

[0002] At present, under-screen fingerprints have been widely used in flexible display modules. In the prior art, this design requires opening a through hole in the heat dissipation film. A black light-shielding tape is usually set above the through hole to protect the part of the display panel that is not blocked by the heat dissipation film, thereby eliminating the difference in display effect between the position of the through hole corresponding to the display panel that is exposed to ambient light due to no heat dissipation film blocking and the position around the through hole that is not exposed to ambient light, causing poor display. However, this through-hole design of the heat dissipation film will cause excessive stress at the opening, and because there is a step difference between the light-shielding tape and the heat dissipation film at this position, the light-shielding tape will exert great pressure on this position when attaching the heat dissipation film, further increasing the stress at this position, causing the back of the display panel to be subjected to unreleasable stress, resulting in fingerprint hole imprints at the opening of the display panel and shadows on the front. Summary of the invention

[0003] In order to solve at least one of the above problems, a first embodiment of the present invention provides a flexible display module.

[0004] include:

[0005] A display panel, a heat dissipation film and a light shielding tape, wherein the heat dissipation film comprises a first film layer, a second film layer and a protective film layer stacked in sequence on a side of the display panel away from the light output, wherein

[0006] The first film layer comprises a first opening therethrough, wherein the first opening corresponds to a sensing area of ​​a fingerprint recognition module to be installed on the flexible display module;

[0007] The second film layer comprises a second opening therethrough, the second opening being arranged corresponding to the first opening to expose the sensing area of ​​the fingerprint recognition module to be installed, and the aperture of the second opening is larger than the aperture of the first opening;

[0008] The protective film layer covers the second film layer;

[0009] The light-shielding tape is arranged on the side of the protective film layer close to the display panel and is located in the second opening, and the orthographic projection of the light-shielding tape on the display panel covers the orthographic projection of the first opening on the display panel.

[0010] Furthermore, a center point of an orthographic projection of the first opening on the display panel coincides with a center point of an orthographic projection of the second opening on the display panel.

[0011] Furthermore, the orthographic projection of the first opening on the display panel, the orthographic projection of the second opening on the display panel, and the orthographic projection of the light-shielding tape on the display panel are axially symmetrical along a first direction;

[0012] and / or

[0013] The orthographic projection of the first opening on the display panel, the orthographic projection of the second opening on the display panel, and the orthographic projection of the light-shielding tape on the display panel are axisymmetric along the second direction.

[0014] Further, the first film layer includes a mesh adhesive layer and a foam layer stacked in sequence on the display panel away from the light emitting side, the first opening includes a first through hole penetrating the mesh adhesive layer and a second through hole penetrating the foam layer, the aperture of the second through hole is larger than the aperture of the first through hole, and the aperture of the second through hole is smaller than the aperture of the second opening;

[0015] and / or

[0016] The second film layer includes a polyimide layer and a copper foil layer stacked in sequence on the first film layer away from the display panel, the second opening includes a third through hole penetrating the polyimide layer and a fourth through hole penetrating the copper foil layer, the aperture of the fourth through hole is larger than the aperture of the third through hole, and the aperture of the third through hole is larger than the aperture of the first opening.

[0017] Furthermore, the display panel includes a non-bending display area and at least one bending display area, and the second film layer of the heat dissipation film is provided with a plurality of grooves penetrating therethrough corresponding to each of the bending display areas.

[0018] Furthermore, the plurality of grooves are regularly arranged elliptical grooves or prismatic grooves.

[0019] A second embodiment of the present invention provides an under-screen fingerprint display device, including a display panel, a heat dissipation film, and a fingerprint recognition module, wherein the heat dissipation film includes a first film layer and a second film layer stacked sequentially on the display panel away from the light emitting side, wherein

[0020] The first film layer includes a first opening therethrough, wherein the first opening corresponds to a sensing area of ​​the fingerprint recognition module;

[0021] The second film layer comprises a second opening therethrough, the second opening being arranged corresponding to the first opening to expose the sensing area of ​​the fingerprint recognition module, and the aperture of the second opening is larger than the aperture of the first opening;

[0022] The fingerprint recognition module is arranged in the first opening and the second opening.

[0023] A third embodiment of the present invention provides a method for manufacturing the above-mentioned flexible display module, comprising:

[0024] Pasting a first film layer on a side of the display panel away from a light emitting side, wherein the first film layer includes a first opening therethrough, and the first opening corresponds to a sensing area of ​​a fingerprint recognition module to be installed on the flexible display module;

[0025] The second film layer is attached to a side of the first film layer away from the display panel, wherein the second film layer includes a second opening therethrough, the second opening is arranged corresponding to the first opening to expose the sensing area of ​​the fingerprint recognition module to be installed, and the aperture of the second opening is larger than the aperture of the first opening;

[0026] The protective film layer is pasted on the side of the second film layer away from the display panel, and a light-shielding tape is provided on the side of the protective film layer close to the display panel, and the light-shielding tape is located in the second opening, and the orthographic projection of the light-shielding tape on the display panel covers the orthographic projection of the first opening on the display panel.

[0027] Furthermore, the display panel includes a non-bending display area and at least one bending display area, and the step of attaching the second film layer to a side of the first film layer away from the display panel further includes:

[0028] The second film layer is provided with a plurality of slots penetrating therethrough corresponding to each of the bent display regions, and the slots are elliptical slots or diamond-shaped slots.

[0029] A fourth embodiment of the present invention provides a method for manufacturing an under-screen fingerprint display device, comprising:

[0030] Forming the flexible display module as described above;

[0031] Peeling off the protective film layer of the heat dissipation film of the flexible display module and the light-shielding tape disposed on the protective film layer;

[0032] The fingerprint recognition module is installed in the first opening and the second opening of the heat dissipation film of the flexible display module, and the sensing area of ​​the fingerprint recognition module is exposed through the second opening and the first opening.

[0033] The beneficial effects of the present invention are as follows:

[0034] In view of the existing problems, the present invention develops a flexible display module, an under-screen fingerprint display device and a manufacturing method, wherein through holes of different apertures are respectively opened in the first film layer and the second film layer of the heat dissipation film to form a first opening and a second opening for installing a fingerprint recognition module, and the aperture of the second opening opened in the second film layer is larger than the aperture of the first opening opened in the first film layer, so that the first film layer can provide support for the opening of the second film layer arranged thereon, thereby reducing the stress at the boundary of the second opening of the second film layer; and a shading tape is arranged on the side of the protective film layer close to the display panel and in the second opening, thereby eliminating the step difference of the original shading tape arranged on the side away from the display panel, so that the covering force can be evenly applied to the heat dissipation film, further reducing the stress at the opening during the module manufacturing process, thereby effectively reducing the mold imprint at the opening of the display panel, making up for the problems existing in the prior art, and having broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1a A schematic diagram showing the structure of a heat dissipation film and a through hole of a flexible display module in the prior art;

[0037] Figure 1b A schematic diagram showing the structure of a heat dissipation film and a light shielding tape of a flexible display module in the prior art;

[0038] Figure 2 A schematic diagram showing the structure of a flexible display module in the prior art is shown;

[0039] Figure 3 A force analysis diagram showing a display panel of a flexible display module in the prior art when a heat dissipation film is attached;

[0040] Figure 4 A schematic diagram showing the structure of a flexible display module according to an embodiment of the present invention is shown;

[0041] Figure 5 A schematic diagram showing projections of the first opening, the second opening and the light-shielding tape on a display panel according to an embodiment of the present invention is shown;

[0042] Figure 6 A force analysis diagram showing a display panel covered with a heat dissipation film according to an embodiment of the present invention;

[0043] Figure 7aA schematic cross-sectional view showing a large-angle bent CG according to an embodiment of the present invention;

[0044] Figure 7b A cross-sectional schematic diagram showing a warping defect of a heat dissipation film according to an embodiment of the present invention;

[0045] Figure 8a-8b A schematic structural diagram showing a heat dissipation film according to an embodiment of the present invention having a plurality of grooves formed in the second film layer;

[0046] Fig. 9 A flow chart of manufacturing a flexible display module according to an embodiment of the present invention is shown;

[0047] Fig.10 A flowchart of manufacturing an under-screen fingerprint display device according to an embodiment of the present invention is shown;

[0048] Fig.11 A schematic diagram showing the structure of an under-screen fingerprint display device according to an embodiment of the present invention is shown;

[0049] Fig.12 A schematic structural diagram of a flexible display module according to another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0050] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0051] It should be noted that the terms “on…”, “formed on…” and “disposed on…” described herein may indicate that one layer is directly formed or disposed on another layer, or may indicate that one layer is indirectly formed or disposed on another layer, i.e., there are other layers between the two layers. In this article, unless otherwise specified, the term “located on the same layer” used means that two layers, parts, components, elements or parts can be formed by the same patterning process, and the two layers, parts, components, elements or parts are generally formed of the same material. In this article, unless otherwise specified, the expression “patterning process” generally includes steps such as coating, exposure, development, etching and stripping of photoresist. The expression “one-time patterning process” means a process of forming patterned layers, parts, components, etc. using a mask.

[0052] like Figure 1a and 1bAs shown, in the prior art, a through hole for installing a fingerprint recognition module is generally opened on the heat dissipation film 12', and a light shielding tape 13' is pasted on the heat dissipation film protective film layer 123' at the position corresponding to the through hole to prevent the display panel corresponding to the through hole from being exposed to ambient light. The cross-sectional schematic diagram of the heat dissipation film at the opening position is shown in FIG. Figure 2 As shown, during the manufacturing process, due to the height difference between the light shielding tape 13 ′ at the opening position and the heat dissipation film protective film 123 ′, the stress at this position will be relatively large when the heat dissipation film is attached. Figure 3 The schematic diagram shows the stress of each film layer under the uniform covering force when the heat dissipation film is attached. Due to the step difference between the light shielding tape 13' and the protective film layer 123', the uniform covering force on the surface will be transmitted to each film layer of the heat dissipation film. The stress of each film layer is the largest at its opening boundary. The stress generated by the light shielding tape 13' under the covering force is also concentrated in the opening area of ​​the display panel 11' to form a mold. Moreover, when subjected to the covering force, the foam layer 1213' of the heat dissipation film will produce Figure 3 The rebound force shown provides support, but the rebound force is smallest at the boundary of the opening, so the stress of the display panel 11 ′ at the opening position is the largest and most concentrated, and the mold imprint of the display panel in the opening area is further aggravated.

[0053] Therefore, the inventors propose a flexible display module, an under-screen fingerprint display device and a manufacturing method to solve the above problems.

[0054] like Figure 4 As shown, an embodiment of the present invention provides a flexible display module 10, including a display panel 11, a heat dissipation film 12 and a light shielding tape 13, wherein the heat dissipation film 12 includes a first film layer 121, a second film layer 122 and a protective film layer 123 stacked in sequence on the display panel 11 away from the light emitting side, wherein:

[0055] The first film layer 121 includes a first opening 1211 extending therethrough, and the first opening 1211 corresponds to a sensing area of ​​a fingerprint recognition module to be installed on the flexible display module;

[0056] The second film layer 122 includes a second opening 1221 extending therethrough, wherein the second opening 1221 is arranged corresponding to the first opening 1211 to expose the sensing area of ​​the fingerprint recognition module to be installed, and the aperture of the second opening is larger than the aperture of the first opening;

[0057] The protective film layer 123 covers the second film layer 122;

[0058] The light-shielding tape 13 is disposed on the side of the protective film layer 123 close to the display panel 11 and located in the second opening 1221 . The orthographic projection of the light-shielding tape 13 on the display panel 11 covers the orthographic projection of the first opening 1211 on the display panel.

[0059] In this embodiment, through holes of different apertures are respectively opened in the first film layer 121 and the second film layer 122 of the heat dissipation film to form a first opening 1211 and a second opening 1221 for installing the fingerprint recognition module, and the aperture of the second opening 1221 opened in the second film layer 122 is larger than the aperture of the first opening 1211 opened in the first film layer 121. The first film layer 121 can provide film layer support for the opening of the second film layer 122 arranged thereon, thereby reducing the stress at the boundary of the second opening 1221 of the second film layer 122; and the shading tape 13 is arranged on the side of the protective film layer 123 close to the display panel 11 and located in the second opening 1221, thereby eliminating the step difference problem caused by the shading tape being arranged on the side away from the display panel in the prior art, so that the covering force can be evenly applied to the heat dissipation film, effectively reducing the stress at the opening during the module manufacturing process, thereby reducing the mold printing at the opening of the display panel, making up for the problems existing in the prior art, and having broad application prospects.

[0060] In a specific embodiment, the specific steps of manufacturing the flexible display module are described as follows:

[0061] In the first step, a first position corresponding to a sensing area of ​​a fingerprint recognition module to be installed on the flexible display module is determined on the first film layer 121 , and a first opening 1211 is formed at the first position.

[0062] In the second step, a second position corresponding to the first opening 1211 and capable of exposing the sensing area of ​​the fingerprint recognition module to be installed is determined on the second film layer 122, and a second opening 1221 is formed at the second position.

[0063] In an optional embodiment, a center point of an orthographic projection of the first opening 1211 on the display panel coincides with a center point of an orthographic projection of the second opening 1221 on the display panel.

[0064] In this embodiment, the first opening and the second opening are both located at positions corresponding to the sensing area of ​​the fingerprint recognition module to achieve effective installation of the fingerprint recognition module, and the center of the orthographic projection of the first opening on the display panel and the center of the orthographic projection of the second opening on the display panel are concentrically arranged. The arrangement of the concentric openings can achieve balanced force on each film layer of the heat dissipation film and reduce the number of mold prints. It is worth noting that the present application does not limit the shapes of the first opening and the second opening, which can be circular, rectangular or other shapes, with balanced force on each film layer as the design criterion, which will not be repeated here.

[0065] In the third step, a third position corresponding to the second opening 1221 and the first opening 1211 is determined on the protective film layer 123 and a light shielding tape is disposed on the third position.

[0066] In this embodiment, the light-shielding tape is arranged on a side of the protective film layer close to the display panel and is located in the second opening. On the one hand, it solves the step difference problem caused by the light-shielding tape being arranged on the protective film layer in the prior art; on the other hand, by utilizing the first opening and the second opening with different apertures, the light-shielding tape is arranged in the second opening, and the orthographic projection of the light-shielding tape on the display panel covers the orthographic projection of the first opening on the display panel, thereby achieving the light-shielding effect of the light-shielding tape on the display panel corresponding to the position of the first opening, avoiding the problem of uneven display caused by part of the display panel being exposed to ambient light, and effectively improving the user experience.

[0067] In order to further balance the stress on the display panel, in an optional embodiment, the orthographic projection of the first opening 1211 on the display panel, the orthographic projection of the second opening 1221 on the display panel and the orthographic projection of the light-shielding tape 13 on the display panel 11 are symmetrical along the first direction.

[0068] In this embodiment, if Figure 5 FIG. 1 shows a top view of the positions of the first opening 1211 and the second opening 1221 on the display panel, wherein the first direction is the horizontal direction X, and the second direction is the Y direction perpendicular to the first direction X. Figure 5 As shown, the orthographic projections of the first opening 1211, the second opening 1221 and the light-shielding tape 13 on the display panel are symmetrical along the axis X' in the first direction. Therefore, the symmetrical arrangement of the first opening, the second opening and the light-shielding tape can further achieve balanced force on each film layer of the heat dissipation film and reduce the number of mold prints.

[0069] Similarly, in another optional embodiment, the orthographic projection of the first opening 1211 on the display panel, the orthographic projection of the second opening 1221 on the display panel, and the orthographic projection of the light-shielding tape 13 on the display panel are symmetrical along the second direction Y axis.

[0070] In this embodiment, if Figure 5 As shown, the orthographic projections of the first opening 1211, the second opening 1221 and the light-shielding tape 13 on the display panel are symmetrical along the axis Y' in the second direction. Therefore, the symmetrical arrangement of the first opening, the second opening and the light-shielding tape can further achieve balanced force on each film layer of the heat dissipation film and reduce the number of mold prints.

[0071] It is worth noting that the orthographic projections of the first opening 1211, the second opening 1221 and the light shielding tape 13 on the display panel can be set to be only along the Figure 5 The first direction shown is axisymmetric, and can also be set to be only along Figure 5 The second direction axis symmetry shown can also be set to be axially symmetric along the first direction and the second direction at the same time to achieve concentric setting of the centers of the three orthographic projections. Technical personnel in this field should design it according to actual application requirements to achieve balanced force on each film layer of the heat dissipation film, which will not be repeated here.

[0072] In the fourth step, the first film layer 121 is adhered to a side of the display panel 11 away from the light emitting side.

[0073] In a fifth step, the second film layer 122 is adhered to a side of the first film layer 121 away from the display panel 11 .

[0074] In the sixth step, the protective film layer 123 is pasted on the side of the second film layer 122 away from the display panel 11, the orthographic projection of the second opening 1221 on the display panel 11 covers the orthographic projection of the light-shielding tape 13 on the display panel 11, and the orthographic projection of the light-shielding tape 13 on the display panel 11 covers the orthographic projection of the first opening 1211 on the display panel 11.

[0075] So far, it has formed Figure 4 The flexible display module shown is compared with Figure 2 The flexible display module in the prior art shown in FIG. 1 has a light shielding tape attached to the side of the protective film layer away from the display panel, and Figure 3 The force analysis shown in Figure 6As shown, the force analysis of the display module of this embodiment is carried out. In this embodiment, the light-shielding tape 13 is attached to the side of the protective film layer 123 close to the display panel, so that the plane of the protective film layer 123 away from the display panel 11 is smooth. When the heat dissipation film is attached, the attaching force can be evenly applied to the protective film layer 123, eliminating the stress generated at the opening by the original light-shielding tape attaching method. In addition, in this embodiment, the aperture of the second opening 1221 is larger than the aperture of the first opening 1211, and the first film layer 121 can provide rebound force support for the boundary of the second opening 1221 of the second film layer 122, reducing the concentrated stress at the opening boundary generated by the original flexible display module due to the second opening boundary and the first opening boundary being the same, thereby reducing the stress concentration of the display panel at the opening, and thus effectively reducing the fingerprint imprint at the opening of the display panel.

[0076] Therefore, in this embodiment, the light-shielding tape is attached to the side of the protective film layer close to the display panel, so that the sticking force of the heat dissipation film can be evenly applied to the protective film layer when it is attached, and the aperture of the second opening opened in the second film layer is set to be larger than the first aperture opened in the first film layer, which can reduce the stress concentration of the display panel at the opening, thereby effectively reducing the fingerprint imprint at the opening of the display panel.

[0077] In order to further reduce the stress on the display panel, in an optional embodiment, Fig.12 As shown, the first film layer 121 includes a mesh adhesive layer 1212 and a foam layer 1213 which are sequentially stacked on the display panel 11 away from the light emitting side, the first opening includes a first through hole penetrating the mesh adhesive layer and a second through hole penetrating the foam layer, the aperture of the second through hole is larger than the aperture of the first through hole, and the aperture of the second through hole is smaller than the aperture of the second opening.

[0078] In this embodiment, by respectively setting a first through hole and a second through hole with gradually increasing apertures, boundary support is further provided for the second opening. Specifically, a first through hole is set in the mesh adhesive layer 1212, and a second through hole is set in the foam layer 1213, and the aperture of the second through hole is larger than the aperture of the first through hole. Then, the mesh adhesive layer 1212 can provide support for the through hole boundary of the second through hole set in the foam layer 1213, thereby reducing stress concentration at the boundary between the second through hole and the first through hole, further reducing the stress borne by the display panel, and being able to effectively reduce the mold imprint of the display panel at the through hole.

[0079] Specifically, a fifth position corresponding to a sensing area of ​​a fingerprint recognition module to be installed on the flexible display module is determined on the grid glue layer, and a first through hole penetrating the grid glue layer is formed at the fifth position;

[0080] Determining a sixth position on the foam layer corresponding to the fifth position, and forming a second through hole penetrating the foam layer at the sixth position;

[0081] The foam layer 1213 is pasted on the side of the grid adhesive layer 1212 away from the display panel 11, the orthographic projection of the second through hole on the display panel covers the orthographic projection of the first through hole on the display panel, and the orthographic projection of the second opening on the display panel covers the orthographic projection of the second through hole on the display panel.

[0082] Similarly, in another optional embodiment, Fig.12 As shown, the second film layer 122 includes a polyimide layer 1222 and a copper foil layer 1223 which are sequentially stacked on the first film layer 121 away from the display panel 11, and the second opening includes a third through hole penetrating the polyimide layer and a fourth through hole penetrating the copper foil layer, the aperture of the fourth through hole is larger than the aperture of the third through hole, and the aperture of the third through hole is larger than the aperture of the first opening.

[0083] In this embodiment, the polyimide layer can form a support for the through-hole boundary of the fourth through-hole opened in the copper foil layer through the third through-hole and the fourth through-hole with gradually increasing apertures, thereby reducing the stress concentration at the boundaries of the third through-hole and the fourth through-hole, further reducing the stress borne by the display panel, and effectively reducing the mold imprint of the display panel at the through-hole.

[0084] Specifically, a seventh position corresponding to the first opening and capable of exposing the sensing area of ​​the fingerprint recognition module to be installed is determined on the polyimide layer, and a third through hole penetrating the polyimide layer is formed at the seventh position;

[0085] Determining an eighth position on the copper foil layer corresponding to the seventh position, and forming a fourth through hole penetrating the copper foil layer at the eighth position;

[0086] The polyimide layer is pasted on the side of the foam layer away from the display panel, the orthographic projection of the third through hole on the display panel covers the orthographic projection of the second opening on the display panel, and the orthographic projection of the fourth through hole on the display panel covers the orthographic projection of the third through hole on the display panel.

[0087] Those skilled in the art may only adopt the first film layer opening method of sequentially opening the first through hole and the second through hole with gradually increasing apertures in the mesh glue layer and the foam layer, or only adopt the second film layer opening method of sequentially opening the third through hole and the fourth through hole with gradually increasing apertures in the polyimide layer and the copper foil layer, or may simultaneously adopt the aforementioned two film layer opening methods to form a through hole design with gradually increasing apertures from the first through hole of the mesh glue layer to the fourth through hole of the copper foil layer. Those skilled in the art should design according to actual applications to achieve that each film layer of the heat dissipation film can provide support for another film layer disposed thereon at the point where the through hole boundary stress is maximum, which will not be elaborated here.

[0088] It is worth noting that, considering that the mesh glue layer and the foam layer of the first film layer form a progressive stepped opening with the second opening of the second film layer, in this embodiment, the aperture of the first opening is the aperture of the first through hole of the mesh glue layer; similarly, the aperture of the second opening is the aperture of the third through hole of the polyimide layer, that is, when the mesh glue layer, the foam layer, the polyimide layer and the copper foil layer form a stepped opening, the aperture of the through hole of each film layer increases from near to far from the display panel.

[0089] On the other hand, the demand for large-angle bending of flexible display modules and their corresponding cover glass (Cover Glass, CG) is becoming increasingly strong. The market has proposed flexible display modules with a bending angle greater than 90°. Therefore, this places extremely high demands on the attachment stability of the heat dissipation film 12 attached to the display panel 11. The cross-sectional schematic diagram of the large-angle bending CG (bending angle>70°) is shown in FIG. Figure 7a As shown, CG30 is covered on the flexible display module, and the heat dissipation film 12 is closely attached to the display panel 11 and bends with the bending of CG. However, the heat dissipation film at the bend tends to return to a flat state after being attached or left to stand, resulting in Figure 7b The heat dissipation film shown in the figure is warping up, and under high temperature and high humidity reliability conditions, this warping phenomenon will be aggravated, seriously affecting the product quality of the display module. To solve this problem, the inventor proposed after a large number of experiments that when the heat dissipation film is in a large-angle bending condition, the heat dissipation film 12 close to the CG side is the outer circle of the bending arc, and the side away from the CG side is the inner circle of the bending arc. Under the same length, the heat dissipation film 12 in the inner circle will have material accumulation, thereby generating internal stress, and the heat dissipation film 12 is subjected to the greatest stress in the bending area. This stress will cause the heat dissipation film originally attached to the display panel 11 at the bending point to warp up, resulting in the following phenomenon: Figure 7b Therefore, in an optional embodiment, the display panel includes a non-bending display area and at least one bending display area, and the second film layer of the heat dissipation film is provided with a plurality of grooves passing through the bending display area corresponding to each bending display area.

[0090] Specifically, Figure 8a As shown, the plurality of slots 1230 are regularly arranged elliptical slots. Figure 8b As shown, the plurality of slots 1230 are regularly arranged prismatic slots. It is worth noting that the present application does not specifically limit the specific slot shape. Those skilled in the art select an appropriate slot shape according to actual application requirements, and the design principle is to prevent the heat dissipation film from warping in the bending area under high temperature and high humidity conditions, which will not be repeated here.

[0091] In this embodiment, by providing a groove at the maximum stress of the bending zone of the heat dissipation film, the bending stress of the film material in the original bending zone is reduced, which can effectively prevent the heat dissipation film in the bending zone from warping.

[0092] Specifically, in the process of manufacturing the flexible display module, determining a second position on the second film layer corresponding to the first opening and capable of exposing the sensing area of ​​the fingerprint recognition module to be installed, and forming a second opening at the second position further comprises:

[0093] A plurality of fourth positions corresponding to the bent display regions are determined on the second film layer, and a groove is formed at each of the fourth positions. The groove is an elliptical groove or a diamond groove.

[0094] That is to say, the second opening and the plurality of grooves can be formed on the second film layer in the same manufacturing process, that is, the patterning of the second opening and the plurality of grooves can be completed using the same manufacturing step, thereby effectively simplifying the process flow.

[0095] It is worth noting that the present application does not specifically limit the position and number of the bending areas of the flexible display module. Those skilled in the art should set them according to the actual application conditions to meet the design criterion of grooving at the maximum stress in the bending area, which will not be elaborated here.

[0096] It should also be noted that, for example, 7a and Figure 7b The positional relationship between the heat dissipation film 12 and the display panel 11 shown is the placement method when the flexible display module is actually used. Figure 2 as well as Figure 4 The positional relationship between the heat dissipation film 11 and the display panel 11 shown is the processing and placement method when the heat dissipation film is attached, that is, no matter which placement method is used, the grid glue layer in the first film layer of the heat dissipation film is always attached to the display panel.

[0097] Corresponding to the flexible display module provided in the above-mentioned embodiments, an embodiment of the present application also provides a method for manufacturing the above-mentioned flexible display module. Since the manufacturing method provided in the embodiment of the present application corresponds to the flexible display modules provided in the above-mentioned embodiments, the previous implementation method is also applicable to the manufacturing method provided in this embodiment and will not be described in detail in this embodiment.

[0098] like Fig. 9 As shown, an embodiment of the present application also provides a method for manufacturing the above-mentioned flexible display module, comprising:

[0099] Pasting a first film layer on a side of the display panel away from a light emitting side, wherein the first film layer includes a first opening therethrough, and the first opening corresponds to a sensing area of ​​a fingerprint recognition module to be installed on the flexible display module;

[0100] The second film layer is attached to a side of the first film layer away from the display panel, wherein the second film layer includes a second opening therethrough, the second opening is arranged corresponding to the first opening to expose the sensing area of ​​the fingerprint recognition module to be installed, and the aperture of the second opening is larger than the aperture of the first opening;

[0101] The protective film layer is pasted on the side of the second film layer away from the display panel, and a light-shielding tape is provided on the side of the protective film layer close to the display panel, and the light-shielding tape is located in the second opening, and the orthographic projection of the light-shielding tape on the display panel covers the orthographic projection of the first opening on the display panel.

[0102] In this embodiment, through holes of different apertures are respectively opened in the first film layer and the second film layer of the heat dissipation film to form the first opening and the second opening for installing the fingerprint recognition module, and the aperture of the second opening is larger than the aperture of the first opening. After the first film layer and the second film layer are pasted together, the first film layer can provide film layer support for the opening of the second film layer arranged thereon, thereby reducing the stress at the boundary of the second opening of the second film layer; and the light-shielding tape is arranged on the side of the protective film layer close to the display panel and located in the second opening, eliminating the step difference problem caused by the light-shielding tape being arranged on the side away from the display panel in the prior art, so that the covering force can be evenly applied to the heat dissipation film, further reducing the stress at the opening during the module manufacturing process, thereby effectively reducing the mold imprint at the opening of the display panel, making up for the problems existing in the prior art, and having broad application prospects. The specific implementation of this embodiment refers to the aforementioned embodiment, which will not be repeated here.

[0103] In an optional embodiment, the display panel includes a non-bending display area and at least one bending display area, and the step of attaching the second film layer to a side of the first film layer away from the display panel further includes:

[0104] The second film layer is provided with a plurality of slots penetrating therethrough corresponding to each of the bent display regions, and the slots are elliptical slots or diamond-shaped slots.

[0105] In this embodiment, by providing a groove at the maximum stress of the bending zone of the heat dissipation film, the bending stress of the film material in the original bending zone is reduced, which can effectively prevent the heat dissipation film in the bending zone from warping. The specific implementation of this embodiment refers to the above embodiment and will not be repeated here.

[0106] Based on the above-mentioned flexible display module and the manufacturing method of the flexible display module, as Fig.10 As shown, an embodiment of the present application also provides a method for manufacturing an under-screen fingerprint display device, including:

[0107] Forming the above-mentioned flexible display module;

[0108] Peeling off the protective film layer of the heat dissipation film of the flexible display module and the light-shielding tape disposed on the protective film layer;

[0109] The fingerprint recognition module is installed in the first opening and the second opening of the heat dissipation film of the flexible display module, and the sensing area of ​​the fingerprint recognition module is exposed through the second opening and the first opening.

[0110] In this embodiment, the protective film layer of the heat dissipation film and the light-shielding tape provided on the protective film layer are first peeled off to expose the first opening and the second opening, and then the fingerprint recognition module is installed in the first opening and the second opening of the heat dissipation film of the flexible display module. The sensing area of ​​the fingerprint recognition module is exposed through the second opening and the first opening, thereby forming an under-screen fingerprint display device with a fingerprint recognition function. The subsequent manufacturing method is the same as the prior art and will not be repeated here.

[0111] According to the above-mentioned method for manufacturing the under-screen fingerprint display device, those skilled in the art can understand that the following under-screen fingerprint display device is also within the protection scope of this application. Fig.11 As shown, an embodiment of the present application provides an under-screen fingerprint display device 20, including a display panel 11, a heat dissipation film 12 and a fingerprint recognition module 21, wherein the heat dissipation film 12 includes a first film layer 121 and a second film layer 122 sequentially stacked on the display panel 11 away from the light emitting side, wherein

[0112] The first film layer 121 includes a first opening 1211 extending therethrough, and the first opening 1211 corresponds to the sensing area of ​​the fingerprint recognition module 21;

[0113] The second film layer 122 includes a second opening 1221 extending therethrough, wherein the second opening 1221 is arranged corresponding to the first opening 1211 to expose the sensing area of ​​the fingerprint recognition module 21, and the aperture of the second opening 1221 is larger than the aperture of the first opening 1211;

[0114] The fingerprint identification module 21 is disposed in the first opening 1211 and the second opening 1221 .

[0115] In this embodiment, the fingerprint recognition module is disposed in the corresponding first opening and second opening, and the sensing area of ​​the fingerprint recognition module is exposed through the second opening and the first opening, thereby forming an under-screen fingerprint display device with a fingerprint recognition function. The specific implementation of this embodiment refers to the above-mentioned embodiment and will not be repeated here.

[0116] In view of the existing problems, the present invention develops a flexible display module, an under-screen fingerprint display device and a manufacturing method. Through holes with different apertures are respectively opened in the first film layer and the second film layer of the heat dissipation film to form a first opening and a second opening for installing a fingerprint recognition module, and the aperture of the second opening opened in the second film layer is larger than the aperture of the first opening opened in the first film layer. The first film layer can provide film layer support for the opening of the second film layer arranged thereon, thereby reducing the stress at the boundary of the second opening of the second film layer; and a shading tape is arranged on the side of the protective film layer close to the display panel and in the second opening, thereby eliminating the step difference of the original shading tape arranged on the side away from the display panel, so that the covering force can be evenly applied to the heat dissipation film, further reducing the stress at the opening during the module manufacturing process, thereby effectively reducing the mold imprint at the opening of the display panel, making up for the problems existing in the prior art, and having broad application prospects.

[0117] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A flexible display module, comprising a display panel, a heat dissipation film and a light shielding tape, characterized in that: The heat dissipation film comprises a first film layer, a second film layer and a protective film layer which are sequentially stacked and arranged on the display panel away from the light emitting side, wherein The first film layer comprises a first opening therethrough, wherein the first opening corresponds to a sensing area of ​​a fingerprint recognition module to be installed on the flexible display module; The second film layer comprises a second opening therethrough, the second opening being arranged corresponding to the first opening to expose the sensing area of ​​the fingerprint recognition module to be installed, and the aperture of the second opening is larger than the aperture of the first opening; The protective film layer covers the second film layer; The light-shielding tape is arranged on a side of the protective film layer close to the display panel and is located in the second opening, and the orthographic projection of the light-shielding tape on the display panel covers the orthographic projection of the first opening on the display panel; The first film layer comprises a mesh adhesive layer and a foam layer which are sequentially stacked on the display panel away from the light emitting side, the first opening comprises a first through hole penetrating the mesh adhesive layer and a second through hole penetrating the foam layer, the aperture of the second through hole is larger than the aperture of the first through hole, and the aperture of the second through hole is smaller than the aperture of the second opening; The second film layer includes a polyimide layer and a copper foil layer stacked sequentially on the first film layer away from the display panel, the second opening includes a third through hole penetrating the polyimide layer and a fourth through hole penetrating the copper foil layer, the aperture of the fourth through hole is larger than the aperture of the third through hole, and the aperture of the third through hole is larger than the aperture of the first opening; The display panel includes a non-bending display area and at least one bending display area. The cover plate covering the flexible display module is bent at a large angle, and the bending angle is greater than 70°. The heat dissipation film fits tightly to the display panel, and the second film layer of the heat dissipation film is provided with a plurality of grooves passing through the bent display areas corresponding to each of the bent display areas.

2. The flexible display module according to claim 1, characterized in that: A center point of an orthographic projection of the first opening on the display panel coincides with a center point of an orthographic projection of the second opening on the display panel.

3. The flexible display module according to claim 1, characterized in that: The orthographic projection of the first opening on the display panel, the orthographic projection of the second opening on the display panel, and the orthographic projection of the light-shielding tape on the display panel are axially symmetrical along a first direction; and / or The orthographic projection of the first opening on the display panel, the orthographic projection of the second opening on the display panel, and the orthographic projection of the light-shielding tape on the display panel are axisymmetric along the second direction.

4. The flexible display module according to claim 1, characterized in that: The plurality of grooves are regularly arranged elliptical grooves or prismatic grooves.

5. An under-screen fingerprint display device, characterized in that: The invention comprises a display panel, a heat dissipation film and a fingerprint recognition module, wherein the heat dissipation film comprises a first film layer and a second film layer stacked in sequence on the display panel away from the light emitting side, wherein The first film layer includes a first opening therethrough, wherein the first opening corresponds to a sensing area of ​​the fingerprint recognition module; The second film layer comprises a second opening therethrough, the second opening being arranged corresponding to the first opening to expose the sensing area of ​​the fingerprint recognition module, and the aperture of the second opening is larger than the aperture of the first opening; The fingerprint recognition module is arranged in the first opening and the second opening; The first film layer comprises a mesh adhesive layer and a foam layer which are sequentially stacked on the display panel away from the light emitting side, the first opening comprises a first through hole penetrating the mesh adhesive layer and a second through hole penetrating the foam layer, the aperture of the second through hole is larger than the aperture of the first through hole, and the aperture of the second through hole is smaller than the aperture of the second opening; The second film layer includes a polyimide layer and a copper foil layer stacked sequentially on the first film layer away from the display panel, the second opening includes a third through hole penetrating the polyimide layer and a fourth through hole penetrating the copper foil layer, the aperture of the fourth through hole is larger than the aperture of the third through hole, and the aperture of the third through hole is larger than the aperture of the first opening; The display panel includes a non-bent display area and at least one bent display area, the under-screen fingerprint display device includes a cover plate covering the display panel, the cover plate is bent at a large angle, and the bending angle is greater than 70°, the heat dissipation film is tightly fitted to the display panel, and the second film layer of the heat dissipation film is provided with a plurality of grooves passing through each of the bent display areas.

6. A method for manufacturing a flexible display module as claimed in any one of claims 1 to 4, characterized in that: include The first film layer is pasted on the side of the display panel away from the light emitting side, the first film layer includes a first opening penetrating therethrough, and the first opening corresponds to the sensing area of ​​the fingerprint recognition module to be installed on the flexible display module; the first film layer includes a grid adhesive layer and a foam layer stacked in sequence on the display panel away from the light emitting side, the first opening includes a first through hole penetrating the grid adhesive layer and a second through hole penetrating the foam layer, and the aperture of the second through hole is larger than the aperture of the first through hole; the second film layer is pasted on the side of the first film layer away from the display panel, the second film layer includes a first through hole penetrating therethrough two openings, the second openings are arranged corresponding to the first openings to expose the sensing area of ​​the fingerprint recognition module to be installed, and the aperture of the second openings is larger than the aperture of the first openings; the second film layer comprises a polyimide layer and a copper foil layer which are sequentially stacked on the first film layer away from the display panel, the second openings comprise a third through hole penetrating the polyimide layer and a fourth through hole penetrating the copper foil layer, the aperture of the fourth through hole is larger than the aperture of the third through hole, and the aperture of the third through hole is larger than the aperture of the first opening, and the aperture of the second through hole is smaller than the aperture of the second opening; A protective film layer is pasted on a side of the second film layer away from the display panel, a light shielding tape is provided on a side of the protective film layer close to the display panel, and the light shielding tape is located in the second opening, and the orthographic projection of the light shielding tape on the display panel covers the orthographic projection of the first opening on the display panel; The display panel includes a non-bending display area and at least one bending display area, the cover plate covering the flexible display module is bent at a large angle, the bending angle is greater than 70°, the heat dissipation film is closely attached to the display panel, and the second film layer is attached to the side of the first film layer away from the display panel further includes: The second film layer is provided with a plurality of openings penetrating therethrough corresponding to each of the bent display regions.

7. The manufacturing method according to claim 6, characterized in that: The grooves are oval grooves or diamond grooves.

8. A method for manufacturing an under-screen fingerprint display device, characterized in that: include: Forming a flexible display module as described in any one of claims 1 to 4; Peeling off the protective film layer of the heat dissipation film of the flexible display module and the light-shielding tape disposed on the protective film layer; The fingerprint recognition module is installed in the first opening and the second opening of the heat dissipation film of the flexible display module, and the sensing area of ​​the fingerprint recognition module is exposed through the second opening and the first opening.

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